Climate Change Flashcards
(55 cards)
1
Q
Define biomes
A
a community of life forms adapted to a large natural area
2
Q
Define anthropogenic biomes
A
biomes that are the result of sustain direct human interaction with ecosystems
3
Q
Abiotic components of ecosystem structure
A
Climatic Factors; sunlight, precipitation, humidity, wind
Inorganic Substances; carbon cycle, nitrogen cycle, water cycle
Organic Substances; lipids, proteins, carbohydrates
4
Q
Biotic components of ecosystem structure
A
Producers: plants
Consumers: Herbivores, carnivores, omnivores
Decomposers: fungi, bacteria
5
Q
Define biodiversity loss
A
The loss of species, genetic or ecosystem diversity
6
Q
Sustainability
A
meeting the needs of current and future generation through simultaneous environmental, social, economic adaption and improvement
7
Q
Define spatial technologies
A
technology that refers to place, space or location; includes technology that collects and organises data
8
Q
Examples of spatial technology
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GPS, Google Earth, satellite images and aerial photographs
9
Q
Function of spatial technologies
A
- analyse relationships between locations
- make decisions on the location of facilities
- map demographics of different populations
10
Q
Define remote sensing
A
obtaining info about the earth’s surface without being in direct contact with the area
11
Q
Examples of remote sensing technology
A
Aircraft, balloons, satellites, space shuttles, sonars on board ships
12
Q
Remote sensing case study - Rondonia
A
Once the site of around 51.4 million acres of forest; around 70 000 km2 cleared over the past 30 years
Initially, forest clearing followed the road networks, which then attracted small-land farmers
Clearing eventuated into more significant areas being cleared for cattle farms
Due to the fishbone pattern, there is a high rate of biodiversity loss; easy human access leads to hunting, poaching, and logging
Satellite Images shows how widespread the deforestation becomes in Rondonia, through the use of satellite images of the same location, at the same angle annually, at approximately the same time of year
13
Q
Reactive Carbon
A
support growth both indirectly and directly; causes smog, acid rain, biodiversity loss
14
Q
The heat budget - insolation
A
31% returned via atmospheric reflection and terrestrial reflection (albedo)
19% absorbed by ozone molecules in stratosphere
Around 50% absorbed by earth’s surface (warming of lower stratosphere)
15
Q
The heat budget - emisson
A
69% of terrestrial radiation is emitted through long-wave radiation
31% leaves through atmospheric reflection
16
Q
The heat budget - terrestrial radiation
A
6% through atmospheric reflection
15% absorbed by gases, water droplets, aerosols
7% heat transfer occurs through conduction
22% latent energy in conduction, sublimation and evaporation
17
Q
Hydrological cycle
A
the movement of water and water vapour through the troposphere
18
Q
Hydrological cycle - condensation
A
water vapour in air rises by convection (looses energy) - temp then drops, changing to liquid/ice
19
Q
Hydrological cycle - precipitation
A
vapour becomes too heavy to remain in the atmospheric air currents, then falls
20
Q
Hydrological cycle - infiltration
A
portion of precipitation that seeps into the earth - varies with slope, vegetation, soil and rock type
21
Q
Hydrological cycle - run-off
A
soils become saturated with water and drains into water bodies at lowest possible point
22
Q
Hydrological cycle - transpiration
A
water reenters the atmosphere through plants
23
Q
Carbon Cycle
A
Carbon enters the biotic environment through autotrophs; extract carbon through photosynthesis
Primary and secondary consumers consume carbon, return it through respiration
Burning of organic carbon-based materials and it’s decay release CO2
24
Q
Carbon cycle - fluctuations and variations
A
Seasonal Fluctuations - decline in CO2 levels in N hemisphere summer due to increased vegetation
Clearing vegetation affects their ability to act as carbon sinks
25
Carbon Cycle - carbon sinks
Removed atmospheric carbon is stored within fossil fuels and calcium carbonate in limestone - forest and woodlands
26
Carbon Cycle - oceanic carbon
Cold temps - increase the removal from the atmosphere, warmer temps increase carbon release
Fossil fuels are only significant long-term carbon sinks in the ocean
27
Implications of Anthropogenic Biomes on Ecosystems
Intensification of agricultural systems, specialisation, globalisation have reduced genetic diversity of plants and animals
Changes in land use - forestry, pasture, irrigated, built-up and ornamental
Increased carbon emissions and reactive carbon
Reactive carbon - support growth both indirectly and directly; causes smog, acid rain, biodiversity loss
Native foliage is removed for agricultural, urban development - decrease is natural, barren lands, increase in urbanised land
Urbanisation = increased GHG emissions, waste removal, population density
Low population density = higher biodiversity, natural plants, bacteria, animals, low carbon emissions; carbon is removed via photosynthesis
High population density = lower biodiversity, introduced species, carbon emissions increase from fossil fuels, transport, deforestation, reactive nitrogen levels rise due to fertilizers and as a by-product of fossil fuels
28
Implications of Anthropogenic Biomes on Ecosystems - loss of food security
local/regional population is resilient in ecological, natural disasters due to access to other sources of agricultural income/food sources
May cause health concerns – access to a variety of foods, maintained plant and animal biodiversity means there are manageable levels of wildlife pathogens that can be passed onto humans (Lymes)
29
Implications of Anthropogenic Biomes on Ecosystems - loss of energy security
wood fuel provides over ½ energy needs in developing countries, accounts for over 80% of fuel needs in Tanzania; women and children spend time travelling long distances to gather wood rather than being educated
30
Implications of Anthropogenic Biomes on Ecosystems - difficulty providing clean water
cheaper and more efficient to maintain a healthy ecosystem in the watershed area rather than filtering water
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Implications of Anthropogenic Biomes on Ecosystems - loss of social relations
indigenous cultures have strong connections to the land; if this is disrupted, they can incur distress and disconnection
32
Implications of Anthropogenic Biomes on Ecosystems - loss of freedom and choice
monoculture cash crops (coffee, bananas) impact on ecosystems
If healthy ecosystems and biodiversity aren’t maintained it can affect ecotourism, cosmetics, medicine
Major consequences for countries that rely heavily on this industry for income; Botswana, Kenya, Zimbabwe
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Implications of Anthropogenic Biomes on Ecosystems - loss of ecosystem services
loss of invasion resistance; non-native species can reduce biodiversity of area – particularly detrimental to biodiversity hotspots (Busselton-Augusta)
34
Implications of Anthropogenic Biomes on Ecosystems - lack of pollination of plants
reduction of bees due to use of pesticides, impact of viruses
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Implications of Anthropogenic Biomes on Ecosystems - impacts climate regulation
effecting carbon storage, albedo, evapotranspiration, rising temperatures and fire regimes
Lack of marine can impact on photosynthesis levels
36
World Population Growth, Affluence and Technology
Population growth increased lots after 1950 - industrial revolution
Higher growth in developing countries as children are required to work, educated women know about/have access to contraception
Increased population growth in urban areas in comparison to rural areas: jobs, urbanisation
Less people available to farm - producing foods; farms are becoming larger, less families involved
Urban sprawl; providing infrastructure (roads, hospitals, schools), bushland is removed - houses are built
As the population increases, cropland increases - forests decline
Temperature increases of >4C will endanger the ability of farm and ecosystems to adapt
Water cycles will be very different and less predictable - Changes in the intensity frequency and seasonality of precipitation, sea level rises and mental glaciers, changing in groundwater and river flows
Drastically change diets, shifting production areas for familiar crops,
As population grows, more food will have to be produced per hectare - 5 people per hectare
Global seafood consumption - 49% farm raised fish (current) vs 62% farm raised fish (2030)
37
Ecosystem services and anthropogenic issues
Food and water - Quality, overexploitation, invasive species
Flood and disease control - Deforestation/building infrastructure on flood plains etc
Cultural services - Important to indigenous populations
Nutrient cycles - Deforestation - changes in water, carbon, nitrogen, oxygen cycles
38
Land Cover Change - Water Cycle
• Damming increases the amount of evaporation and filtration in the area
• Any altering of land cover change that impacts surface and vegetation of watershed area will increase run off, erosion and sediment deposition
• Irrigation depletes rivers and water tables, increases nutrient run-off; eutrophication
• Deforestation reduces transpiration and raises water table
• Pollutants change the nature of precipitation
o Acid rain caused by high levels of sulphuric acid in China and New York
• Overuse of ground water for drinking, irrigation and industrial use impacts the water table
39
Land Cover Change - Soil erosion and degradation
Supports biodiversity
• Greater demand for agricultural commodities (palm oil, coffee, cotton) leads to land cover change for agriculture
o Grasslands and forests become crops
• Soil erosion, compaction of soils, loss of soil structure, nutrient degradation and soil salinity
• Soil erosion – less fertile land (loss of topsoil), increased pollution from fertiliser, clogged water ways are more prone to flooding – lost water retention
• Caused by deforestation, overgrazing and agrochemicals
o Loss of arable land, clogged/polluted waterways, increased flooding
40
Land Cover Change - Loss of habitat and biodiversity
* Occurred due to expansion of agricultural land, increased demand for timber, overgrazing
* Tropical rainforests are most at risk – contain 50% of world’s biodiversity
* Mitigation – combining traditional land techniques with modern science
41
Land Cover Change - degradation of aquatic and marine environments
• Pollution – chemicals and effluent causing habitat damage
• Eutrophication – excess nutrients (fertilisers) enter water, cause algal bloom
o Reduces oxygen levels – marine and aquatic life dies
• Ocean acidification – dramatic rise in CO2 in atmosphere, ocean becomes more acidic
• Damming – stops the normal flow of sediment downstream; affects physical processes and habitats
o Changes the water temperature and level of nutrients
o Sediment and nutrients from the Congo River provide a carbon sink; fast moving water is replaced with stagnant water – supports mosquito borne diseases
o China’s 3 Dam project – cause people to resettle
42
Land Cover Change - Regional climates and urban heat islands
Caused due to the removal of natural surfaces which absorb and use a greater level of the heat with materials that are non-reflective and water resistant – radiate more heat
43
Global Temperature Patterns
Dependant on the amount of insolation received in an area
Areas closer to the equator are warmer than polar regions
The difference in in temperatures creates a global transfer of heat (atmospheric circulation)
44
Global Precipitation Patterns
Equator – highest rainfall occurs; strong heating causes large uplift of moist air
Mid-latitude temperate regions – moderate levels of precipitation; development of cold fronts within low pressure systems
Precipitation decreases further inland
Higher altitudes result in cooler temperatures
45
Natural Climate Change - Factors
- Fluctuations in amount of insolation
- Orbital variation
- Atmospheric composition of GHG (volcanic eruptions)
- Changes in albedo
- Variance in ocean currents
46
Anthropogenic Climate Change - Factors
• Enhanced greenhouse effect – increasing the amount of radiation trapped neat the earth’s surface and accelerating warming
• Natural sources of carbon dioxide are more than 20x greater than sources due to human activity; natural sources are closely balanced by natural sinks (weathering of continental rocks, photosynthesis) – remained balanced until the industrial revolution
• CO2 is most important GHG – 60% of enhanced greenhouse effect
o Methane – 20%
• Upper 75m of ocean warming by 0.11°C per decade
47
Ice Cores
* Ice cores provide information on temperature, precipitation, atmospheric composition, volcanic activity, wind patterns
* Thickness of each layer shows how much snow fell in one year, several cores taken from the same location shows the wind patterns
* Chemical composition of the snow shows temperatures; colder temps = higher concentration of a particular oxygen isotope in the snow
* Bubbles trapped within the ice capture atmospheric gas concentrations – shows 800 000 years of past climates
* Vostok Ice Core – 1987; 3190m, longest ice core on record, sampled to an age of 800 000 years BP
48
Rising Oceanic Temperatures
• Argo floats sent temperature, pressure and salinity data to satellites
• Gathered through MODIS satellites (Moderate Resolution Imaging Spectroradiometer); used since 2000
• Oceans are warmer, with higher sea levels than ever recorded
• Accounts for 90% of energy accumulated since 1971 and 2010
o More than 60% of total energy increase in the climate system is stored in the upper ocean, about 30% in the ocean below 700m
• Predicted that regions of high salinity and evaporation will become more saline, those with low salinity and high precipitation have become fresher since 50s
o Regional trends in ocean salinity provide indirect evidence that evaporation and precipitation over oceans have changed
• Sea surface temperatures in Australia have warmed by 0.9°C since 1900
o Been well above average since 2010; haven’t had below-average sea surface temperatures since 1994
• Mean sea level have increased globally over last 150 years; 2012 – sea levels were 225mm higher than 1880
o Thermal expansion, melting of glaciers and ice sheets
49
Changes in surface reflectivity
• Consistent increase in global temperatures corresponding with a decrease in snow and ice cover
o Less energy being reflected and more absorbed by ground and water – positive feedback loop; ice-albedo feeback
• Deforestation – increases albedo; burning biomass releases CO2 into atmosphere and the vegetation has been removed to photosynthesis it
o Initial cooling is followed by a warming trend
• Urban heat island – asphalt and concrete absorb heat rather than reflect it
o Decreased albedo, reduced atmospheric circulation, waste heat from urban processes, lack of evapotranspiration
50
Changes in carbon cycle
• Disturbs natural carbon seqestration
• Deforestation and related increased carbon emissions occurring primarily in the tropics
• Soils contain around 1500 gigatonnes of organic carbon; more than vegetation and atmosphere
• Deforestation followed by agriculture causes the further release of soil carbon – tillage
o Brazil; increased price for soy beans push farmers into forested areas of the Amazon
• Also contributes to methane (altered surface hydrology, wetland drainage, rice paddies, cattle grazing), nitrous oxide (agriculture, fertiliser, biomass combustion)
• Modification of agricultural practises – can act as an effective carbon sink; offsetting as much as 20% of CO2 emissions annually
51
Effects of Climate Change - Temperature rise
• Average surface air temperature has risen by more than 0.7°C over the last century
• Worst impact for developing countries
• IPCC predicts a rise of between 1.1°C to 6.4°C over the next century
o Not a uniform increase; higher latitudes will be more affected
o CSIRO – Number of hot days will increase in Australia’s north
52
Effects of Climate Change - Ice sheets and glaciers
• Glacier retreat – decreased by 50% since the end of the 19th century
• Glacier retreat in the Andes, Alps, Himalayas, Rocky Mountains
• Direct effects:
o Landslides, flash floods, glacial lake overflow
• Indirect effects:
o Increase in annual variation of river flow
• Himalayan Glacier could disappear by 2035
o Sources of Asia’s biggest rivers
o 2.4 billion people live in these drainage basins – floods then drought
o River water provides water – drinking and farming
• Antarctic and Greenland Ice Sheets
o Greenland glacier loss to up to 30m per day
o Artic ice sheets expected to disappear by 2100
o Antarctic ice sheets melting faster than can be replaced by snow; sea level rise by 2100 could exceed by 1m
53
Effects of Climate Change - Coastal Systems
• IPCC predicted global warming would lead to sea level rise between 0.09 to 0.88m by end of century
• London and New Orleans have barriers against storm surges
• Will affect low lying nations; Tuvalu – leave population homeless and stateless
• Impact on coastal cities with over 10 million people will be most severe
o 40% of world’s population live within 100km of the coast
• Water and sanitation systems will be placed under strain
• Deteriorating infrastructure (ports and communication) could lead to administrative and financial crisis
• Sea level rise of 0.4m of Bay of Bengal would lead to 11% of coastal land underwater; 7-10 million climate refugees
• Impact:
o Increased coastal erosion
o Higher storm surge flooding; increased flood risk
o Coastal inundation
o Changes in surface water quality
o Movement on sea water into fresh water –affect water quality
54
Effects of Climate Change - Coral Reefs
• Coral bleaching – caused by
o High sea surface temps
o Wind exposure at low tide
o Anthropogenic and natural factors
o Once bleaching begins, tends to continue even if stress factor is removed
• Great Barrier Reef:
o Two major bleaching – 1998 and 2002
o Some areas suffered severe damage – 90% of corals killed
o IPCC predicts the coral will be more susceptible to frequent bleaching events
• 90% lost in Maldives, Sri Lanka, Kenya, Tanzania, Seychelles
• Coral can be in a weakened state – prone to diseases; black/white band disease
o Won’t be able to adapt fast enough to keep pace with climate change
55
Effects of Climate Change - Vegetation
• Shift in climate belts – affects forests in particular
• Weather patterns change with increased temp, availability of water
• Canadian forests among the most vulnerable – account for 10% of world’s forest cover
• Increasing impact of pests
o Pine forests in North America more susceptible to pine beetle – longer breeding periods
o Since of 1998 lack of severe winters
o Dead forests act as a carbon source
• Increased risk of forest fires
o Longer, warmer summers in western USA – 4x increase in fires
• Fire in Australia
o Earlier start in fire season
o More frequent and intense fire
o Shorter intervals between fires may alter ecosystems and threaten biodiversity
• Impact of increased CO2 on plant growth
o Promote plant growth and photosynthetic activity
o Higher CO2 levels will only increase growth up to a point
